Separation and determination of cations in beverage products by capillary zone electrophoresis

J Chromatogr A. 2006 Jun 16;1118(1):144-50. doi: 10.1016/j.chroma.2006.04.030. Epub 2006 May 8.

Abstract

Cation determination is important for quality control of beverage products. To determine a large group simultaneously, a capillary electrophoresis procedure is developed with indirect UV at 214 nm in a three-complex buffer system (10 mM N,N-dimethylbenzylamine (DBA), 8 mM lactic acid and 2 mM 18-crown-6) with good mobility matching with desired cations. Under optimized conditions with pH adjusted to 4.65, a baseline separation is achieved for 14 cations (Rb(+), NH(4)(+), K(+), Ca(2+), Na(+), Mg(2+), Mn(2+), Co(2+), Fe(2+), Cd(2+), Cr(3+), Ni(2+), Zn(2+) and Cu(2+)) within 7 min using an uncoated silica column. To cover ng/l to mug/l range, both hydrostatic and electrokinetic sampling are studied, showing working ranges within (0.05-50)/(0.005-2) microg/l and detection limits (13-78)/(1.4-10) ng/l, respectively with satisfactory repeatability (RSD 0.31-0.47% for migration time, and 3.0-4.0% for peak height measurement). Agreeable results with established inductively coupled plasma-atomic emission spectrometry method have been obtained for orange juice and tea samples.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Beverages / analysis*
  • Buffers
  • Cations / analysis*
  • Cations / isolation & purification
  • Citrus sinensis / chemistry
  • Electrophoresis, Capillary / methods*
  • Reproducibility of Results
  • Spectrophotometry, Ultraviolet
  • Tea / chemistry

Substances

  • Buffers
  • Cations
  • Tea